The Small Animal Imaging Resource provides imaging using multiple modalities including depth resolved or planar fluorescence and bioluminescent imaging, MRI, PET/CT, and planar scintigraphy. A number of experienced investigators and technical staff capable of undertaking imaging and assisting in data interpretation are associated with the Resource. There is infrastructure for animal handling (e.g., anesthesia, infusion, monitoring vital signs) and can facilitate and undertake developmental studies for implementation of new imaging protocols and evaluation of methods. The Resource is supported by a radiochemistry laboratory and molecular synthesis laboratory and has computer capabilities for data analysis and archiving. The Small Animal Imaging Resource has been promoting and enhancing cellular and molecular imaging for the last 10 years and has developed substantial infrastructure. Regular seminars and symposia have stimulated increasing interest among scientists and physicians from diverse backgrounds (engineers, chemists, molecular biologists, and oncologists) to apply imaging to questions in oncology and this has been recognized by grants to several individuals. The Resource supported in part by a U24 SAIRP (Pis Ralph Mason and Dean Sherry) commenced in April 2007. The Resource serves as a catalyst for new collaborations and focus for coordinating new infrastructure, e.g., winning NIH Shared instrumentation grants for a Caliper (Xenogen) Spectrum in 2008 and Institutional investment in small animal MRI and PET/CT. Imaging (radiology) and histology (pathology) are the cornerstones of most clinical rounds and diagnoses. Increasingly, imaging is filtering down to small animal research, coinciding with the availability of optimized imaging instrumentation. There is a realization that progress in molecular biology and drug design must move to assessment in vivo. Imaging allows animals (tumors) to serve as their own controls, substantially improving research efficiency. In many cases, animal models (e.g., transgenic and knockout) are exceedingly costly and/or in short supply. Many reagents, e.g., novel therapeutic antibodies are available only in small quantities. Fewer animals are needed, saving on cost and meeting ethical goals for biomedical research. Thus, maximizing the information and quality of data obtained from individual subjects should enhance research efficiency and ultimate translation to the clinic.